// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_RENDERER_PEPPER_PLUGIN_MODULE_H_
#define CONTENT_RENDERER_PEPPER_PLUGIN_MODULE_H_

#include <map>
#include <memory>
#include <set>
#include <string>

#include "base/files/file_path.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "base/native_library.h"
#include "base/process/process.h"
#include "content/common/content_export.h"
#include "content/public/common/pepper_plugin_info.h"
#include "ppapi/c/pp_bool.h"
#include "ppapi/c/pp_instance.h"
#include "ppapi/c/ppb_core.h"
#include "ppapi/c/private/ppb_instance_private.h"
#include "ppapi/shared_impl/ppapi_permissions.h"

typedef void* NPIdentifier;

class GURL;

namespace base {
class FilePath;
}

namespace ppapi {
class CallbackTracker;
} // namespace ppapi

namespace IPC {
struct ChannelHandle;
}

namespace blink {
class WebPluginContainer;
} // namespace blink

namespace content {
class HostDispatcherWrapper;
class PepperPluginInstanceImpl;
class PepperBroker;
class RendererPpapiHostImpl;
class RenderFrameImpl;
struct WebPluginInfo;

// Represents one plugin library loaded into one renderer. This library may
// have multiple instances.
//
// Note: to get from a PP_Instance to a PepperPluginInstance*, use the
// ResourceTracker.
class CONTENT_EXPORT PluginModule : public base::RefCounted<PluginModule>,
                                    public base::SupportsWeakPtr<PluginModule> {
public:
    typedef std::set<PepperPluginInstanceImpl*> PluginInstanceSet;

    // You must call one of the Init functions after the constructor to create a
    // module of the type you desire.
    //
    // The module lifetime delegate is a non-owning pointer that must outlive
    // all plugin modules. In practice it will be a global singleton that
    // tracks which modules are alive.
    PluginModule(const std::string& name,
        const std::string& version,
        const base::FilePath& path,
        const ppapi::PpapiPermissions& perms);

    // Sets the given class as being associated with this module. It will be
    // deleted when the module is destroyed. You can only set it once, subsequent
    // sets will assert.
    void SetRendererPpapiHost(std::unique_ptr<RendererPpapiHostImpl> host);

    // Initializes this module as an internal plugin with the given entrypoints.
    // This is used for "plugins" compiled into Chrome. Returns true on success.
    // False means that the plugin can not be used.
    bool InitAsInternalPlugin(const PepperPluginInfo::EntryPoints& entry_points);

    // Initializes this module using the given library path as the plugin.
    // Returns true on success. False means that the plugin can not be used.
    bool InitAsLibrary(const base::FilePath& path);

    // Initializes this module for the given out of process proxy. This takes
    // ownership of the given pointer, even in the failure case.
    void InitAsProxied(HostDispatcherWrapper* host_dispatcher_wrapper);

    // Creates a new module for an external plugin instance that will be using the
    // IPC proxy. We can't use the existing module, or new instances of the plugin
    // can't be created.
    scoped_refptr<PluginModule> CreateModuleForExternalPluginInstance();

    // Initializes the external plugin module for the out of process proxy.
    // InitAsProxied must be called before calling InitAsProxiedExternalPlugin.
    // Returns a result code indicating whether the proxy started successfully or
    // there was an error.
    PP_ExternalPluginResult InitAsProxiedExternalPlugin(
        PepperPluginInstanceImpl* instance);

    bool IsProxied() const;

    // Returns the peer process ID if the plugin is running out of process;
    // returns |base::kNullProcessId| otherwise.
    base::ProcessId GetPeerProcessId();

    // Returns the plugin child process ID if the plugin is running out of
    // process. Returns 0 otherwise. This is the ID that the browser process uses
    // to idetify the child process for the plugin. This isn't directly useful
    // from our process (the renderer) except in messages to the browser to
    // disambiguate plugins.
    int GetPluginChildId();

    static const PPB_Core* GetCore();

    // Returns whether an interface is supported. This method can be called from
    // the browser process and used for interface matching before plugin
    // registration.
    // NOTE: those custom interfaces provided by ContentRendererClient will not be
    // considered when called on the browser process.
    static bool SupportsInterface(const char* name);

    RendererPpapiHostImpl* renderer_ppapi_host()
    {
        return renderer_ppapi_host_.get();
    }

    // Returns the module handle. This may be used before Init() is called (the
    // proxy needs this information to set itself up properly).
    PP_Module pp_module() const { return pp_module_; }

    const std::string& name() const { return name_; }
    const std::string& version() const { return version_; }
    const base::FilePath& path() const { return path_; }
    const ppapi::PpapiPermissions& permissions() const { return permissions_; }

    PepperPluginInstanceImpl* CreateInstance(RenderFrameImpl* render_frame,
        blink::WebPluginContainer* container,
        const GURL& plugin_url);

    // Returns "some" plugin instance associated with this module. This is not
    // guaranteed to be any one in particular. This is normally used to execute
    // callbacks up to the browser layer that are not inherently per-instance,
    // but the helper lives only on the plugin instance so we need one of them.
    PepperPluginInstanceImpl* GetSomeInstance() const;

    const PluginInstanceSet& GetAllInstances() const { return instances_; }

    // Calls the plugin's GetInterface and returns the given interface pointer,
    // which could be NULL.
    const void* GetPluginInterface(const char* name) const;

    // This module is associated with a set of instances. The PluginInstance
    // object declares its association with this module in its destructor and
    // releases us in its destructor.
    void InstanceCreated(PepperPluginInstanceImpl* instance);
    void InstanceDeleted(PepperPluginInstanceImpl* instance);

    scoped_refptr<ppapi::CallbackTracker> GetCallbackTracker();

    // Called when running out of process and the plugin crashed. This will
    // release relevant resources and update all affected instances.
    void PluginCrashed();

    bool is_in_destructor() const { return is_in_destructor_; }
    bool is_crashed() const { return is_crashed_; }

    // Reserves the given instance is unique within the plugin, checking for
    // collisions. See PPB_Proxy_Private for more information.
    //
    // The setter will set the callback which is set up when the proxy
    // initializes. The Reserve function will call the previously set callback if
    // it exists to validate the ID. If the callback has not been set (such as
    // for in-process plugins), the Reserve function will assume that the ID is
    // usable and will return true.
    void SetReserveInstanceIDCallback(PP_Bool (*reserve)(PP_Module, PP_Instance));
    bool ReserveInstanceID(PP_Instance instance);

    // These should only be called from the main thread.
    void SetBroker(PepperBroker* broker);
    PepperBroker* GetBroker();

    // Create a new HostDispatcher for proxying, hook it to the PluginModule,
    // and perform other common initialization.
    RendererPpapiHostImpl* CreateOutOfProcessModule(
        RenderFrameImpl* render_frame,
        const base::FilePath& path,
        ppapi::PpapiPermissions permissions,
        const IPC::ChannelHandle& channel_handle,
        base::ProcessId plugin_pid,
        int plugin_child_id,
        bool is_external);

    // In production we purposely leak the HostGlobals object but in unittest
    // code, this can interfere with subsequent tests. This deletes the
    // existing HostGlobals. A new one will be constructed when a PluginModule is
    // instantiated.
    static void ResetHostGlobalsForTest();

    // Attempts to create a PPAPI plugin for the given filepath. On success, it
    // will return the newly-created module.
    //
    // There are two reasons for failure. The first is that the plugin isn't
    // a PPAPI plugin. In this case, |*pepper_plugin_was_registered| will be set
    // to false and the caller may want to fall back on creating an NPAPI plugin.
    // the second is that the plugin failed to initialize. In this case,
    // |*pepper_plugin_was_registered| will be set to true and the caller should
    // not fall back on any other plugin types.
    static scoped_refptr<PluginModule> Create(RenderFrameImpl* render_frame,
        const WebPluginInfo& webplugin_info,
        bool* pepper_plugin_was_registered);

private:
    friend class base::RefCounted<PluginModule>;
    ~PluginModule();
    // Calls the InitializeModule entrypoint. The entrypoint must have been
    // set and the plugin must not be out of process (we don't maintain
    // entrypoints in that case).
    bool InitializeModule(const PepperPluginInfo::EntryPoints& entry_points);

    std::unique_ptr<RendererPpapiHostImpl> renderer_ppapi_host_;

    // Tracker for completion callbacks, used mainly to ensure that all callbacks
    // are properly aborted on module shutdown.
    scoped_refptr<ppapi::CallbackTracker> callback_tracker_;

    PP_Module pp_module_;

    // True when we're running in the destructor. This allows us to write some
    // assertions.
    bool is_in_destructor_;

    // True if the plugin is running out-of-process and has crashed.
    bool is_crashed_;

    // Manages the out of process proxy interface. The presence of this
    // pointer indicates that the plugin is running out of process and that the
    // entry_points_ aren't valid.
    std::unique_ptr<HostDispatcherWrapper> host_dispatcher_wrapper_;

    // Non-owning pointer to the broker for this plugin module, if one exists.
    // It is populated and cleared in the main thread.
    PepperBroker* broker_;

    // Holds a reference to the base::NativeLibrary handle if this PluginModule
    // instance wraps functions loaded from a library.  Can be NULL.  If
    // |library_| is non-NULL, PluginModule will attempt to unload the library
    // during destruction.
    base::NativeLibrary library_;

    // Contains pointers to the entry points of the actual plugin implementation.
    // These will be NULL for out-of-process plugins, which is indicated by the
    // presence of the host_dispatcher_wrapper_ value.
    PepperPluginInfo::EntryPoints entry_points_;

    // The name, version, and file location of the module.
    const std::string name_;
    const std::string version_;
    const base::FilePath path_;

    ppapi::PpapiPermissions permissions_;

    // Non-owning pointers to all instances associated with this module. When
    // there are no more instances, this object should be deleted.
    PluginInstanceSet instances_;

    PP_Bool (*reserve_instance_id_)(PP_Module, PP_Instance);

    DISALLOW_COPY_AND_ASSIGN(PluginModule);
};

} // namespace content

#endif // CONTENT_RENDERER_PEPPER_PLUGIN_MODULE_H_
